(a) Field of the Invention
The present invention relates to a hybrid vehicle, and more particularly, to a creep control device and method for a hybrid vehicle, which control the driving of a motor according to the distance to a preceding vehicle in order to provide creep driving once the hybrid vehicle has come to a complete stop.
(b) Description of the Related Art
An automatic transmission installed in a typical internal combustion engine vehicle transmits power from an engine through a torque converter, and provides creep driving so that the vehicle moves slightly even when the accelerator pedal is not pressed, while operating in lower speeds and the vehicle is in Drive (D) or reverse (R). This allows a vehicle to get take off smoothly, and may help the vehicle avoid rolling backward when the vehicle is very slowly moving or temporarily stopping and then starting up an inclined road.
In order to reduce costs and minimize the loss of torque transmitted to an automatic transmission, a hybrid vehicle has an engine clutch installed between an engine and a motor instead of a torque converter. Such a hybrid vehicle that does not have a torque converter installed typically includes an engine that enters an idle stop state when stationary, performs motor-driven creep driving to reduce the dissimilarity to typical passenger vehicles and provide comfortable drivability.
In a hybrid vehicle, creep torque may vary depending on whether the brake pedal is deployed and whether the vehicle is stationary. For example, when the brake pedal is deployed and the vehicle is stationary, torque output is not required so that creep torque is controlled to a minimum value—but not to “0” in consideration of the vehicle's off-the-line responsiveness.
Such a hybrid vehicle typically generates creep torque even at a standstill, in view of take off responsiveness, whereby unnecessary driving of the motor occurs, causing draining of the battery. Accordingly, repeated charging and discharging of the battery by the engine may occur, causing deteriorated fuel efficiency, and the repeated charging and discharging may cause a reduction in battery efficiency.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.